China can make good products. Most people don't have quality issues with Apple products. That said, I have yet to run into an optic made in China that equaled a bottom end Japan built optic. In fact, every Chinese made optic I've bought has been a let down. You may not always get what you pay for, but you certainly don't get more with any Chinese made and assembled optic I've seen.
I wouldn't doubt the glass in Leupold's bottom line scopes come from China. They aren't amazing to look through. But they do carry Leupold's warranty and are built and serviced in the US. If a Chinese built optic goes bad, you simply get another. Even with a lifetime warranty, spending $25 in shipping on a $50 scope that breaks in another year is a bad deal. Ignoring glass quality, which I've found is much nicer with the bottom priced Japan optics, things like turret feel, turret travel/repeatability/precision, AO/magnification adjustment, eye relief and eye placement sensitivity, eye strain, etc all are better on the $300+ range non-China made optics. The entire package is better in every way.
All optics will break at some point. Even the well respected brands have issues now and then. Overall, there is a clear performance difference up to the $300-$500 price point(depending on features). Over that you typically see diminishing returns. In my experience, a $300 Leupold/Burris/Nikon is more than 3x nicer than a $100 Chinese made option. While I'm all for a bargain, I'll never go back to the bottom priced optics. There isn't one I've had (and I've had a bunch) that left me satisfied after a year worth of use. If money was real tight, I'd rather not shoot while saving for a $300 scope rather than buy a $100-$150 Chinese made optic.
